Natural Science Forum / Physics / Acoustics / February 2005

Does anyone have (or no of a site where I can get) some measured data on
regenerated noise from attenuators.
Particularly interested in upstream noise.

I'd like to calculate sound insulation for partitions with 2 or 3 air
spaces. I'm especially interested in the case of windows. Does anyone
know about relevant papers I could find on the net? If someone knows
about papers with measurement results of different kind of windows,

Folks,
I often need to assess the effectiveness of different absorbers at low
frequencies. Above 100 Hz absorption can be measured reliably in a lab's
reverb room, but I'm much more interested in testing at frequencies below

Can anyone explain this to me in very simple terms? How does a sound
reflect off thin air? Cheers,
Rory

I would like to know if there exist any freeware/shareware/software to
calculate the acoustic performance of dissipative silencer in
industrial application?
Parameters such as flow rate, air temperature, duct size ... must be

Hey all,
I'm helping someone with an industrial dust collector. The collector is
generating a 40 Hz tone that we're trying to eliminate. We've traced the
tone to the exhaust duct (which kind of makes sense since the duct is 31

I am accessing the news trough the News.individual.net.
I would like to know if there is another FREE news server
out there.
Thanks in advance.

I have a single-car garage I want to isolate as much as possible.
Not full-band iso, but loud electric guitar iso.
It's concrete block, no windows. Concrete block should
isolate well, as I understand it. Is this correct?

I am tortured by impact noises coming from upstairs.
I sleep with inserts "earsoft" and with a muffler "peltor optime 3".
What else defense to add?
What do you think of a insulated cabinet?

Does anyone have a circuit for one these?
Thanks
Richard

Deos anyone know about the error analysis associated with Muller's method?
Please keep it simple.
yours
Richard

I would like to deflect a 125 KHz ultrasound pulse by 90 degree under water
in the simplest possible way.
If I used a plate of material at 45 degrees to the beam how can I ensure
that as much energy as possible is deflected and not either absorbed by the

I want to hear the smell of my feet.What can I do?

Hello to everyone,
I am measuring the complex wave number in an impedance tube, using a
configuration with three equally spaced microphone positions. It works quite
well for the real part, but I don't really know how to deal with the results

Anyone know of this?